![]() | |||||||||||||
Messages in this thread |
Jens Axboe writes: > Doesn't look like it's needed at all, at least you never turn on highmem > I/O with ide_toggle_bounce() :-) Foo, neither I do. :( > BTW, it would be ok to export that from ide-dma.c instead of duplicating > it in ide-pmac. Looking at it again, both ide_build_sglist and ide_raw_build_sglist do *almost* what we want. If ide-pmac used hwif->sg_table instead of pmif->sg_table, and if ide_[raw_]build_sglist were exported and took the maximum number of entries as a parameter instead of using the PRD_ENTRIES constant, then ide-pmac wouldn't need to have its own versions of those routines. Would those changes be OK? Ben, any reason why we have to use pmif->sg_table rather than hwif->sg_table? > Also, can you grow sg segments indefinitely? Each DBDMA (descriptor-based DMA) command has a 16-byte length field, so is limited to 65535 bytes. There is code in pmac_ide_build_dmatable to create multiple DBDMA commands from a single scatterlist element if necessary. We should limit the lengths of the segments instead, then we could have a 1-1 correspondence of scatterlist elements to DBDMA command blocks. Paul. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2005-03-22 12:28 [from the cache] ©2003-2008 | |||||||||||||